The invention relates to an assembly for detecting when a seal has been broken, e.g. a door opened or goods removed from a surface, and recording that event.
A seal in the meaning of an arrangement which is so constructed that a change in the state of the seal, such as the opening of a door or the dispatch of goods can be clearly detected subsequently is, of course, encumbered with serious problems, such as high costs and unreliability in operation.
The present invention relates to an arrangement by means of which an object can be sealed extremely reliably and with a high degree of flexibility at relatively low cost.
According to one aspect of the present invention an assembly is provided comprising the following components: A door mounted in, and for movement with respect to, a door frame. An electrical switch activated in response to movement of a portion of the door away from the door frame. And, an information carrier (e.g. smart card) mounted on said frame and recording each activation of the switch. The assembly may further comprise a clock unit mounted on the door frame for supplying the date and clock time to the information carrier for recordation thereof each time the switch is activated. The switch may comprise a permanent magnet activated switch mounted on the door frame, and a permanent magnet may be mounted on the door for cooperation with the switch. The door is hinged at a first side thereof and the magnet may be mounted on a second side of the door opposite the first side. The switch is mounted on the door frame adjacent the second side of the door. The information carrier can also record each deactivation of the switch.
An information carrier reader may be mounted in contact with the information carrier. Also an acknowledgment unit may be provided in contact with the information carrier for transmitting the identity of a person opening the door for recordation by the information carrier.